Can anyone suggest a source for, or methods to fabricate target scales to allow accurate measurements to be taken from photogrammetry images? I've seen examples of target scales with machine readable circular codes and other useful scaling aids, but haven't found a good affordable source for them. I've also heard that some photogrammetry software packages come with printable coded scales that can be attached to a suitable support, but I don't see this in the trial version of Agisoft's software that I have. Some different sizes/lengths would be useful for smaller objects as well as for larger objects and scenes (within the limits of close-range photogrammetry). I've been using various metal scales, a foldable wood ruler, and a contractor's level, but would like to get the most accurate measurements possible.
Many thanks!
Taylor